hey my friend. if its the brushless set up on the pro try to keep the motor and esc under 200 degrees f. any hotter and magnets loose strength. this will over time cause the motor to fail. i fun mine around 150-175. if its too cold then its going to just going to wear esc out due to the strain the esc is getting pulled on. so just watch the temp.
then i would check your brushes often. and keep the heat a low as possible try putting some other pinions on and see if that helps the heat. heat in brushed motors can cause meltdowns. and if they go unchecked you can weld your motors stator to its rotor. also to much strain can wear out your brushes. sometimes going up in pinion size can help too. and with the higher speed from the 12t motor youmightneed that.